Wires, cables, and the like are commonly installed by pulling the same through a pre-installed conduit. Herein, the term wire is used to describe the various types of wires, cables, fiber optic cables, and the like which are used. Construction of industrial or commercial buildings commonly involves placing conduits in the walls, floors, or ceilings of the building and installing wires or cables in the conduit after construction of that portion of the building has been completed. Similarly, municipal wires and cables are often pulled through underground conduits in order to install the cables.
When installing wires, a rope or other pulling line is first threaded through the conduit. One end of the pulling line is then connected to the wire, typically via a pulling grip, and a pulling machine is attached to the other end of the pulling line and used to pull the wire through the conduit via the pulling line. The pulling machine will typically exert a force on the order of thousands of pounds in order to pull the wire through the conduit. Lengthy conduits, bends in the conduit and the stiffness of the wire itself all contribute to the high pulling force required to pull wires through a conduit.
It is highly desirable to pull a wire through a conduit without loss of connection to the wire, damage to the wire or pulling grips, or other incident. If damage or lost connection to the wire occurs while installing the wire, the wire must typically be removed from the conduit. The wire is typically not usable again, resulting in lost time and lost materials. In many instances, multiple wires are installed simultaneously in a conduit. This may be the case where main power lines are being installed, where multiple communications lines are being installed, etc. In such a situation, a lost connection or damage to a single wire will require removal of all of the wires.
It will thus be appreciated that it is desirable to improve the reliability of the wire pulling grips and associated devices so as to reduce or eliminate the possibility that connection to the wire is lost or that the wire is damaged.
While installing wire, it is often necessary to guide the wire pulling grips and equipment and the wire into the conduit. Where multiple wires are being installed simultaneously, it may be difficult for an operator to guide the grips and wire into the conduit. In such a situation it would be convenient to have a device which bundles the wires and pulling grips together to make it easier to feed these into the conduit.
The pulling grips and associated equipment are periodically damaged while installing wire. In some cases, the grips are damaged when a shoulder or fastener which is part of the grip gets caught on the conduit while feeding the grip into the conduit. In other cases, the pulling grips may be damaged as they slide along the inside of the conduit. If the grips are damaged they must be replaced, resulting in additional costs. Perhaps more importantly, however, significant time may be lost in replacing the grips. It is thus desirable to reduce the risk that the wire pulling grips and associated equipment is damaged while installing the wire.
Additionally, it is desirable to keep the wire pulling grips clean while they are being used. The conduit is often somewhat dirty on the inside. The conduit may contain cement and other debris from construction, metal pieces from manufacturing, etc. Additionally, lubricant is often used while installing wires to reduce the damage to the wire and to reduce the force necessary to pull the wire through the conduit. The debris and lubricant typically coats the wire pulling grips while these are used. The lubricant and debris make the grips more difficult to use, get the operator dirty, and may reduce the effectiveness of the grips in gripping the wire. It is thus often necessary to clean the wire grips. The wire pulling grips may thus be cleaned between pulls as well as after the days use. Pulling grips often include a twisted or braided cable with an eyelet and a cylindrical grip body attached thereto, and thus requires some time to clean. A significant amount of time may thus be spent cleaning wire pulling grips during a day.
It is further desirable to reduce the risk of injury while installing wires into conduit. Wire pulling grips typically have a number of places such as the eyelet or the grip body where an operator's finger, glove, etc. may get caught. This may occur as the operator is guiding a plurality of wire pulling grips into a conduit at the beginning of a wire pull. As the wire pulling machine is located at the other end of the conduit and operated by another person, the wire pulling machine may not be stopped in time should the operator become entangled in the wire pulling grip. Because a significant amount of force is used to pull the wires through the conduit, the operator may well lose or seriously damage a hand or finger if it becomes caught in the wire pulling grip. It is thus desirable to enclose the wire pulling grips during use to reduce the risk of injury.